This invention relates to a vane compressor for use in an air conditioner for automotive vehicles, and more particularly to improvements in the rotor used in a vane compressor of this kind for the purpose of reducing the weight of the rotor.
A vane compressor for use in an air conditioner for automobile vehicles is already known, e.g. from U.S. Pat. No. 3,834,846 issued Sep. 10, 1974, which is of the type including a rotary shaft arranged to be rotated by an associated prime mover; a rotor secured to the rotary shaft for rotation in unison therewith, the rotor having a plurality of axial slits formed in its outer peripheral surface; a plurality of vanes radially movably received in the axial slits; and a housing within which the rotor and the vanes are accommodated, the rotor, the vanes and the housing cooperating to define pump working chambers between them, wherein a refrigerant pumping action is carried out by the rotation of the rotor.
The rotor of such type vane compressor is machined from a carbon steel blank, and is formed therein with a central through bore extending along its axis, through which the rotary shaft extends, a back pressure chamber intersecting with the central through bore and having a diameter larger than the latter bore, and a plurality of vane-receiving axial slits extending substantially tangentially to the central through bore, opening in its outer peripheral surface and communicating with the back pressure chamber.
The rotor of such type is heavy in weight due to the presence of solid portions between adjacent ones of the axial slits, which results in consumption of a great deal of energy supplied from the prime mover in rotatively driving the rotor. Furthermore, the presence of the back pressure chamber with a diameter larger than that of the central through bore, renders the casting or machining operation of the rotor complicated and difficult to carry out.